列印列表中出現前十的元素，可以利用列表的count屬性，可以計數，然後根據數量多少排序 來輸出元素

a = [1,"b","b",3,3,3,"d","d","d","d",5,5,5,5,5,"f","f","f","

f","f","f",7,7,7,7,7,7,7,"h","h","h","h","h","h","h","h",9,9

,9,9,9,9,9,9,9,"j","j","j","j","j","j","j","j","j","j",11,11

,11,11,11,11,11,11,11,11,11]

b = {} #定義空字典

for d in set(a): #去重複的值，set

b[a.count(d)] = d #去重後做計數，把數量和值寫到字典b

for e in reversed(sorted(b.keys())[-10:]):

print e,":",b[e] #排序列表鍵值並取後10個（數量最大的10個），翻轉後打印出數量與值。